1. Field of the Invention
This invention relates to the utilization of wind energy, and more specifically, to the utilization of wind energy through the use of wind turbines.
2. Prior Art
A wind turbine is a machine for converting the kinetic energy of wind into mechanical energy. All of the known wind turbines can produce useful energy only as a result of sufficient wind speed. Generally speaking, the bigger is the wind turbine, the larger is the amount of useful energy that it can produce. On the other hand, the bigger is the size of wind turbine, the higher is the wind speed required for the wind turbine to produce useful energy. However, there are many locations in the world where the prevailing wind speeds are too low for the known wind turbines to produce useful energy. Accordingly, the capabilities of current wind turbines to practically utilize wind energy are limited.
U.S. Pat. No. 6,942,454 to Ohlmann (2005) discloses a vertical axis wind turbine. However, this wind turbine cannot be used for producing a high power output because the turbine is limited to only two rotors. Additionally, the structure of the wind turbine disclosed in Ohlmann is ill-equipped for production because it is non-rigid and unreliable and can operate under only low wind speeds and when rotors are short.